The copper market is often referred to as "Dr. Copper" due to the central nature of copper as a metal in the world economy. Increased economic activity, particularly in construction, usually shows up in a higher price for copper. There are speculators in copper as well and if the speculators on balance think things are picking up they will bid up the price of copper....
Perhaps it is just a supply problem.
Copper has not gone anywhere in years. Even with the latest worldwide rounds of QE and interest rate cuts.
Charts of JJC, the copper ETF.